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Mortality related to convulsive disorders in a developing country in Asia: trends over 20 years
Seizure 1995; 4:273-277
Mortality related to convulsive disorders in a developing country in Asia: trends over 20 years NIMAL SENANAYAKE & HIMALI PEIRIS
Department of Medicine, Faculty of Medicine, University of Peradeniya, Peradeniya, Sri Lanka Address for correspondence: Prof. Nimal Senanayake, Faculty of Medicine, Peradeniya, Sri Lanka
The cause of death as recorded in 37 125 death certificates (DC) issued in the Kandy District over 20 years at five-year intervals beginning 1967 was analysed to determine the trends in mortality caused by convulsive disorders in the community. Convulsions accounted for 881 (23.7/1000) deaths, the highest number being in infancy (35.8%). A slight male preponderance of 51.5% was observed. Most of the deaths occurred in the periphery (51.6%) and in the tea estates (36.3%) as opposed to town area (12.0%). "Febrile convulsions" was the most common diagnosis in 396 (44.9%) deaths. 'Convulsions" which included neonatal and infantile convulsions accounted for 186 (21.1%) deaths. Other causes included chest complications (60, 6.8%), drowning (28, 3.2%), asphyxia (20, 2.3%), status epilepticus (19, 2.2%), burns (7, 0.8%), and poisoning (2, 0.2%). The proportion of deaths due to convulsive disorders showed a decrease from 37.28/1000 in 1967 to 9.55/1000 in 1987, which was most evident in the periphery, from 60.49/1000 to 13.19/1000. This parallelled a drop in the proportion of deaths attributed to "febrile convulsions' and 'convulsions'. The study shows the need to educate the public about first-aid and the subsequent management of convulsions, especially in childhood. Health personnel in developing countries should consider it mandatory to make a specific diagnosis in children who present as febrile convulsions. Appropriate antiepileptic medication and compliance can prevent death due to status epilepticus and injuries associated with seizures. Key words: epilepsy: convulsions: mortality: developing countries: tropics.
INTRODUCTION
Epilepsy and convulsive disorders constitute a c o m m o n neurological problem in developing countries in the tropics t. The condition is more prevalent in tropical countries than in t e m p e r a t e countries, and in certain African and South American countries the prevalence rates exceed 20/1000 population z. In Sri Lanka, a house-tohouse survey conducted in the District of Kandy in the early 1980s revealed that 9 out of 1000 in the general population had experienced two or more epileptic seizures in their lifetime x4. An annual age-adjusted study of mortality for 33 countries has shown that mortality rates for epilepsy are also higher in the tropics than in t e m p e r a t e countries -~. Hardly any studies from developing countries have examined their pattern of mortality due to convulsive disorders. We used death certificate (DC) counterfoils for the past two decades as a data source to determine trends in mortality caused by epilepsy and convulsive disorders in the Kandy District. 1059-1311/95/040273 + 05 $12.00/0
MATERIALS AND METHODS
Kandy District is one of the three administrative districts of the Central Province of Sri Lanka. The district has a land mass of about 2 175 km-" (3.3% of the total land mass of the country) spreading over dales and valleys which a c c o m m o d a t e tea plantations and terraced paddy fields. The population of the district is 1 048317 (1981 census), 7.6% of the total population of Sri Lanka. A b o u t 75% of the people are rural, and there is a considerable population of tea estate workers of 11.6%. A state-run free health service provides the bulk of the health care, delivered through 23 rural hospitals, nine peripheral units, 11 district hospitals, one base hospital, and two general (teaching) h o s p i t a l s - - o n e in Kandy and the other in Peradeniya. Preventative care is provided by a team of health workers headed by 11 medical officers of health. An independent private health sector functions predominantly in urban and suburban areas. Health p a r a m e t e r s for the district for 1987 include life expectancy at birth 66 years, © 1995 British Epilepsy Association
N. S e n a n a y a k e & H. Peirls
274
infant mortality rate 28/1000 live births, birth rate 24/1000, and crude death rate 7.2/1000 population. The District Registrar's Office in Kandy saves DC counterfoils under three geographical divisions, namely town area, peripheries, and estates. Town area contains DCs issued in the Kandy municipal area, which includes the Kandy General Hospital, a peripheral hospital, four private hospitals, and after 1980, the Peradeniya Teaching Hospital. Periphery contains DCs issued outside the municipal limits (except the estates), and includes the district hospitals and the peripheral units. Estates contain DCs issued in the tea estates of the Kandy district. We studied the counterfoils of DCs issued in the Kandy District over 20 years at five-year intervals beginning 1967, and noted the age at death, sex, date of death, and cause of death as recorded in the DC.
RESULTS There were 37 125 DCs in the five years: 7214 in 1967, 9345 in 1972, 8637 in 1977, 6692 in 1982 and 5237 in 1987. Town area contained 12887 DCs, periphery 13068, and estates 11 170. Of these, 881 were deaths related to convulsive disorders, accounting for 23.7/1000 total deaths (TD). Periphery recorded the highest number and the highest proportion of deaths was related to convulsive disorders 455 (34.8/1000 TD), while estates recorded 320 (28.7/1000 TD), and town area 106 (8.2/1000 TD) (Fig. 1). The age at death ranged from birth to 91 years with a median of 2 years; 315 (35.8%) deaths occurred in infancy, and 302 (34.3%) from 1 to 5 years of age (Fig. 2). 140 120
10o -~ 80 .~ 60 z
40 20
0
1967
1972
1977
1982
1987
Fig. 1: Number of deaths related to convulsive disorders in the Kandy District during 1967 to 1987 at five-year intervals. (3, Town; m, periphery; [], estates.
160 140 120
.'~ I00 8O E z
60 40
20 0
<1 Mo I Mo--
6-10
11-20
21-40
>40Yr
Fig. 2: Age and sex distribution of deaths related to convulsive disorders. FI, Town; m, periphery; [], estates.
A slight male preponderance of 51.5% was observed. There was no appreciable difference in the age and sex distribution in the three geographical areas. Causes of death recorded in the DCs, for the total group and for those over the age of five years are given in the Table 1. 'Febrile convulsions' was the most commom cause accounting for 396 (44.9%) deaths in the total group. 'Convulsions' was a heterogenous group which comprised convulsions (63 deaths), neonatal convulsions (52), prematurity and convulsions (13), infantile convulsions (33), and convulsions complicated by worm infestation (25). Chest complications which accounted for 60 deaths included bronchitis, pneumonia and asthma. The miscellaneous causes included convulsions related to various infections, congenital malformations, and head injury following convulsions. Of these, 'febrile convulsions', 'convulsions', chest complications, and asphyxia were most common in the under five-year age group, whereas status epilepticus, drowning, burns, head injuries, and poisoning were most common in the over five-year age group. The age at death due to some of the common causes is shown in Figs 3a and b. The proportion of deaths due to convulsive disorders showed a decrease from 37.28/1000 in 1967 to 9.55/1000 in 1987. This trend was most evident in the periphery, from 60.49/1000 in 1967 to 13.19/1000 in 1987 (Fig. 4a). There has also been a marked drop in the proportion of deaths attributed to 'febrile convulsions' and 'convulsions' (Fig. 4b).
DISCUSSION This study shows that convulsive disorders are an important cause of mortality in the Kandy
M o r t a l i t y related to c o n v u l s i v e
275
disorders
Table 1: Causes of death related to convulsive disorders for all ages and for those over the age of 5 years All ages
Febrile convulsions Convulsions Malnutrition Chest complications Drowning Asphyxia Status epilepticus Burns Poisoning Miscellaneous TOTAL
Age > 5 years
T
P
E
Total %
T
P
E
Total %
24 22 8 8 2 12 14 3 l 12 106
302 20 80 11 20 5 0 3 1 13 455
71 146 31 41 6 3 5 1 0 16 320
396 186 119 60 28 20 19 7 2 41 881
1 4 6 1 2 2 9 3 1 4 32
27 12 77 1 20 4 0 2 1 9 126
5 20 25 3 6 3 5 1 0 9 72
33 36 108 5 28 9 14 6 2 22 230
44.9 21.1 13.5 6.81 3.17 2.27 2.15 0.79 0.22 4.65 100
14.3 15.6 46.9 2.2 12.2 3.9 6.1 2.6 0.9 9.6 100
T, Town, P, Periphery, E, Estates.
70
(a) 60 200 180 /
50
(a)
160
40
-,
140 "o
30
120
~6 100
20
!,
E
80
~
60 _
'\\ \
,-
.
\
/
20 <1
I-5
6-10
1/-15
16-20
8
I
21-25
26-30
31-35
36-40
""
>40
(b)
7
i
6 -
5
z
3
/ \
/
\
~
/',
I
~
i
,,
i
:
/..",,
I
; i
~,
'\
-.-" "" "" ~
"~" '~. ,,~.
i
1967
1972
18 .
.
.
1977
lff
] 2 -\\ 10
\\ \\
'
"/I
.. •, . - . . . -
--.-._'- ~.. ........ ..~ .....
11-15
16-20
21-25
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~
-
, ..... 6-10
1987
.
I I-5
1982
-.
iA
2
0 r <1
~ ~ .~ ~ ~ ~ ~
0 , . ,
8
.
"'. ~ ' ~ . • •
l0
40 _
4
r
31-35
36-40
:,40
Fig. 3: a, Age at death due to febrile convulsions, convulsions, chest complications and malnutrition. - - , Febrile convulsions; - - , convulsions; ---, chest complications; . . . . , malnutrition, b, Age at death due to status epilepticus, burns and drowning. - - . , status epilepticus;---, burns; , drowning.
1967
1972
1977
~ ..... 1982
. 1987
Fig. 4: a, Proportion of deaths related to convulsive disorders in the three geographical divisions during 1967 to 1987 at five-year intervals. &, Town; II, periphery; 4,, estates, b, Proportion of deaths due to four common causes in the three geographic divisions during 1967 to 1987 at five-year intervals. II, Febrile convulsions; 4,, convulsions; ,t, malnutrition; O, chest complications.
276
District, accounting for 23.7 deaths per 1000 total deaths during the 20-year period. Over 70% of the deaths occurred in infancy and early childhood, and most of the deaths occurred outside the town area. The most common cause accounting for the deaths was 'febrile convulsions'. Most of the deaths (76%) attributed to febrile convulsions were from the periphery, and in the periphery 'febrile convulsions' was the most frequent (66.4%) diagnosis of deaths related to convulsive disorders. Febrile seizures are a common acute neurologic disturbance of childhood. A house-to-house survey of 577 families in the Kandy District revealed that 4.73% of the children had experienced febrile convulsions in the past 6. Febrile seizures are generally considered a benign condition. But, the very high mortality attributed to febrile convulsions in the DCs raises the question whether the seizures accompanying fevers in the tropics are 'febrile seizures' in the way the term is used in the West, or in fact the result of direct cerebral insult from infection 7. Osuntokun s remarked that febrile convulsions in the African child was not a benign condition. In Nigeria, the mortality of febrile convulsions was 28%, and the morbidity (hemiplegia, cortical blindness, iatrogenic burns with subsequent contractures, conjunctivitis, etc.) was high 9. Among survivors of febrile convulsions, 30% developed recurrent nonfebrile seizures within a period of five years I°. The present study shows that children who develop febrile seizures, particularly in the periphery, succumb to the underlying disease without proper diagnosis or treatment, and the deaths are attributed to 'febrile seizures'. 'Convulsions', the next most common diagnosis was made largely in the estates (78%), where it was the most frequent (45.6%) diagnosis of deaths related to convulsive disorders. 'Convulsions' included neonatal convulsions, prematurity and convulsions, infantile convulsions, and convulsions complicated by worm infestation. It is likely that central nervous system and other infections presenting with seizures came under this category. The perceived relationship between convulsions and worm infestations is noteworthy. Worm infestations are common in rural areas and estates. Worm infestation by itself does not cause convulsions, but a patient may vomit round worms during febrile illnesses and following seizures, which probably is the basis for the association between convulsions and worm infestation. Malnutrition complicating convulsions was another unusual diagnosis, most common
N. Senanayake & H. Peiris
(67.2%) in the periphery, which affected children as well as adults. These presumably are patients with frequent seizures who are neglected and become malnourished. Chest complications as the cause of death was most frequent (68.3%) in the estates, which is a reflection of the poor management of convulsive seizures. Forcing medicine and other liquids by mouth during or soon after a convulsion is common practice in these areas. Traditional physicians, in addition, administer medicinal oils through nasal passages as a treatment for convulsions. These practices have, no doubt, contributed to the high incidence of chest complications following convulsions in rural areas. Status epilepticus accounted for 2.15% of the deaths. There was no specific age group for the deaths. Most of the deaths were recorded in the Town area, presumably from the two general hospitals. However, there were some deaths in the estates attributed to status epilepticus, which meant that they died before transfer to a general hospital in the city. Drowning accounted for 3.17% of the deaths, and the victims were adolescents and adults. Most of the deaths had occurred in the periphery. In most villages, the source of drinking water is a well, which very often, is unprotected. For bathing, most villagers use a well or a stream. Patients with epilepsy can die by falling into a well or a stream during a seizure. Deaths due to burns had occurred mainly in the periphery or in the town. Some of the deaths recorded in the town area were probably patients transferred from the periphery to hospitals in the city. Because electricity is not available in rural areas, people use makeshift kerosene bottle-lamps. With slight disturbance these lamps can topple spilling kerosene and causing a fire. Children do their school work keeping a bottle-lamp on the desk at arm's length, and those with epilepsy are at risk of burns during a seizure. Similarly, women with epilepsy run the risk of burns in the kitchen because food is cooked using firewood in open hearths. Deaths due to poisoning were presumably suicides, rather than accidental overdosing with antiepileptic drugs. Sri Lanka has a very high incidence of suicide, and self-poisoning is by far the most preferred method II. Pesticides are the most common agent used ~-', which is much more lethal than an overdose of antiepileptic drugs. Patients with uncontrolled epilepsy, because of the physical disability as well as the social unacceptance and stigma may resort to suicide by taking poison. The mortality figures for drowning,
Mortality related to convulsive disorders
burns, and poisoning related to convulsions in this study are probably an underestimate, because the diagnosis of epilepsy could have escaped mention in the death certificate in many other cases. The mortality due to convulsive disorders showed a marked decrease during the 20-year period, and it was most evident in the periphery. This decrease is probably due to a decrease in the number of cases diagnosed as 'febrile convulsions' and 'convulsions'. It is likely that because of better public awareness and improved health facilities, children with convulsions receive early medical attention and correct treatment for the underlying disease. While appreciating the limitations of epidemiological studies based on DC, we believe that our data which compare the pattern of mortality in the Kandy District over two decades provide useful insight into the causes of death related to convulsive disorders in a developing tropical country. Standardized mortality ratios could not be computed, because the reference population for the study could not be defined. This is largely because patients are transferred from other districts for specialized care, and deaths of such patients registered in the Kandy District can give a spuriously high mortality rate. However, the proportional mortality ratios reported in our study highlight the causes of death which are most frequent in people with convulsive disorders. Although a decrease in the mortality ratio has been observed during the 20-year period, it can be reduced further by taking preventative measures. The public needs to be educated about the correct management of childhood convulsions. Special emphasis should be made about the dangers of forcing medicine and other fluids orally or intranasally into an unconscious person. With regard to epilepsy, early medical intervention can minimize the physical and psychological trauma caused by recurrent seizures. The community project in the Kandy District in the early 1980s revealed that more than half the number of patients with epilepsy detected at the survey were not taking any medical treatment -~. Appropriate antiepileptic medication and compliance can
277
prevent or at least reduce the incidence of complications such as status epilepticus and injuries associated with seizures. General advice should be given to patients and their families to avoid dangers during a seizure. Precautions such as replacing makeshift bottle-lamps with better designed safety lamps will be of benefit not only to patients with convulsive disorders, but to the rural poor in general, in preventing unfortunate home accidents which may cause permanent disability or cost their lives.
REFERENCES 1. Senanayake, N. and Roman, G.C. Epidemiology of epilepsy in developing countries. Bulletin of the World Health Organization 1993" 71: 247-258. 2. Senanayake, N. and Roman, G.C. Epidemiology of epilepsy in the tropics. Journal of Tropical and Geographical Neurology 1992" 2: 10-19. 3. Senanayake, N. Epilepsy control in a developing country: the challenge of tomorrow. Ceylon Medical Journal 1987; 32: 181-99. 4. Senanayake, N. and Meinardi, H. Improvement of the care for people with epilepsy in rural areas of a developing country In: Advances of Epileptology. Vol. 17 (Eds J. Manelis, E. Bental, J.N. Loeber and F.E. Dreifuss). New York, Raven Press, 1989: pp. 441-444. 5. Massey, E.W. and Schoenberg, B.S. Mortality from epilepsy, international patterns and changes over time. Neuroepidemiology 1985; 4" 65-70. 6. Sanmuganathan, P.S. and Senanayake, N. An epidemiological study of febrile seizures in a rural community in Sri Lanka. Neurology India 1994; 42(Suppl. 4): 33. 7. Senanayake, N. and Roman, G.C. Aetiological factors of epilepsy in the tropics. Journal of Tropical and Geographical Neurology 1991; 1: 69-80. 8. Osuntokun, B.O. Malaria and the nervous system. African Journal of Medical Science 1983; 12: 165-172. 9. Osuntokun, B.O., Odeku, E.L. and Sinnettee, C.H. Convulsive disorders in Nigerians. East African Medical Journal 1969; 46: 385-394. 10. Osuntokun, B.O. Treatment of epilepsy with special reference to developing countries. Progress in Neuropsychopharmacology 1979; 3: 81-94. 1 I. Weerackody, C. Some features of attempted suicide in Sri Lanka. In: Suicide in Sri Lanka (Ed. P. de Silva). Kandy, Institute of Fundamental Studies, 1989: pp. 41-50. 12. Senanayake, N. and Peiris, H. Mortality due to poisoning in a developing agricultural country: trends over 20 years. Human and Experimental Toxicology 1995; 14: (in press).
Mortality related to convulsive disorders in a developing country in Asia: trends over 20 years NIMAL SENANAYAKE & HIMALI PEIRIS
Department of Medicine, Faculty of Medicine, University of Peradeniya, Peradeniya, Sri Lanka Address for correspondence: Prof. Nimal Senanayake, Faculty of Medicine, Peradeniya, Sri Lanka
The cause of death as recorded in 37 125 death certificates (DC) issued in the Kandy District over 20 years at five-year intervals beginning 1967 was analysed to determine the trends in mortality caused by convulsive disorders in the community. Convulsions accounted for 881 (23.7/1000) deaths, the highest number being in infancy (35.8%). A slight male preponderance of 51.5% was observed. Most of the deaths occurred in the periphery (51.6%) and in the tea estates (36.3%) as opposed to town area (12.0%). "Febrile convulsions" was the most common diagnosis in 396 (44.9%) deaths. 'Convulsions" which included neonatal and infantile convulsions accounted for 186 (21.1%) deaths. Other causes included chest complications (60, 6.8%), drowning (28, 3.2%), asphyxia (20, 2.3%), status epilepticus (19, 2.2%), burns (7, 0.8%), and poisoning (2, 0.2%). The proportion of deaths due to convulsive disorders showed a decrease from 37.28/1000 in 1967 to 9.55/1000 in 1987, which was most evident in the periphery, from 60.49/1000 to 13.19/1000. This parallelled a drop in the proportion of deaths attributed to "febrile convulsions' and 'convulsions'. The study shows the need to educate the public about first-aid and the subsequent management of convulsions, especially in childhood. Health personnel in developing countries should consider it mandatory to make a specific diagnosis in children who present as febrile convulsions. Appropriate antiepileptic medication and compliance can prevent death due to status epilepticus and injuries associated with seizures. Key words: epilepsy: convulsions: mortality: developing countries: tropics.
INTRODUCTION
Epilepsy and convulsive disorders constitute a c o m m o n neurological problem in developing countries in the tropics t. The condition is more prevalent in tropical countries than in t e m p e r a t e countries, and in certain African and South American countries the prevalence rates exceed 20/1000 population z. In Sri Lanka, a house-tohouse survey conducted in the District of Kandy in the early 1980s revealed that 9 out of 1000 in the general population had experienced two or more epileptic seizures in their lifetime x4. An annual age-adjusted study of mortality for 33 countries has shown that mortality rates for epilepsy are also higher in the tropics than in t e m p e r a t e countries -~. Hardly any studies from developing countries have examined their pattern of mortality due to convulsive disorders. We used death certificate (DC) counterfoils for the past two decades as a data source to determine trends in mortality caused by epilepsy and convulsive disorders in the Kandy District. 1059-1311/95/040273 + 05 $12.00/0
MATERIALS AND METHODS
Kandy District is one of the three administrative districts of the Central Province of Sri Lanka. The district has a land mass of about 2 175 km-" (3.3% of the total land mass of the country) spreading over dales and valleys which a c c o m m o d a t e tea plantations and terraced paddy fields. The population of the district is 1 048317 (1981 census), 7.6% of the total population of Sri Lanka. A b o u t 75% of the people are rural, and there is a considerable population of tea estate workers of 11.6%. A state-run free health service provides the bulk of the health care, delivered through 23 rural hospitals, nine peripheral units, 11 district hospitals, one base hospital, and two general (teaching) h o s p i t a l s - - o n e in Kandy and the other in Peradeniya. Preventative care is provided by a team of health workers headed by 11 medical officers of health. An independent private health sector functions predominantly in urban and suburban areas. Health p a r a m e t e r s for the district for 1987 include life expectancy at birth 66 years, © 1995 British Epilepsy Association
N. S e n a n a y a k e & H. Peirls
274
infant mortality rate 28/1000 live births, birth rate 24/1000, and crude death rate 7.2/1000 population. The District Registrar's Office in Kandy saves DC counterfoils under three geographical divisions, namely town area, peripheries, and estates. Town area contains DCs issued in the Kandy municipal area, which includes the Kandy General Hospital, a peripheral hospital, four private hospitals, and after 1980, the Peradeniya Teaching Hospital. Periphery contains DCs issued outside the municipal limits (except the estates), and includes the district hospitals and the peripheral units. Estates contain DCs issued in the tea estates of the Kandy district. We studied the counterfoils of DCs issued in the Kandy District over 20 years at five-year intervals beginning 1967, and noted the age at death, sex, date of death, and cause of death as recorded in the DC.
RESULTS There were 37 125 DCs in the five years: 7214 in 1967, 9345 in 1972, 8637 in 1977, 6692 in 1982 and 5237 in 1987. Town area contained 12887 DCs, periphery 13068, and estates 11 170. Of these, 881 were deaths related to convulsive disorders, accounting for 23.7/1000 total deaths (TD). Periphery recorded the highest number and the highest proportion of deaths was related to convulsive disorders 455 (34.8/1000 TD), while estates recorded 320 (28.7/1000 TD), and town area 106 (8.2/1000 TD) (Fig. 1). The age at death ranged from birth to 91 years with a median of 2 years; 315 (35.8%) deaths occurred in infancy, and 302 (34.3%) from 1 to 5 years of age (Fig. 2). 140 120
10o -~ 80 .~ 60 z
40 20
0
1967
1972
1977
1982
1987
Fig. 1: Number of deaths related to convulsive disorders in the Kandy District during 1967 to 1987 at five-year intervals. (3, Town; m, periphery; [], estates.
160 140 120
.'~ I00 8O E z
60 40
20 0
<1 Mo I Mo--
6-10
11-20
21-40
>40Yr
Fig. 2: Age and sex distribution of deaths related to convulsive disorders. FI, Town; m, periphery; [], estates.
A slight male preponderance of 51.5% was observed. There was no appreciable difference in the age and sex distribution in the three geographical areas. Causes of death recorded in the DCs, for the total group and for those over the age of five years are given in the Table 1. 'Febrile convulsions' was the most commom cause accounting for 396 (44.9%) deaths in the total group. 'Convulsions' was a heterogenous group which comprised convulsions (63 deaths), neonatal convulsions (52), prematurity and convulsions (13), infantile convulsions (33), and convulsions complicated by worm infestation (25). Chest complications which accounted for 60 deaths included bronchitis, pneumonia and asthma. The miscellaneous causes included convulsions related to various infections, congenital malformations, and head injury following convulsions. Of these, 'febrile convulsions', 'convulsions', chest complications, and asphyxia were most common in the under five-year age group, whereas status epilepticus, drowning, burns, head injuries, and poisoning were most common in the over five-year age group. The age at death due to some of the common causes is shown in Figs 3a and b. The proportion of deaths due to convulsive disorders showed a decrease from 37.28/1000 in 1967 to 9.55/1000 in 1987. This trend was most evident in the periphery, from 60.49/1000 in 1967 to 13.19/1000 in 1987 (Fig. 4a). There has also been a marked drop in the proportion of deaths attributed to 'febrile convulsions' and 'convulsions' (Fig. 4b).
DISCUSSION This study shows that convulsive disorders are an important cause of mortality in the Kandy
M o r t a l i t y related to c o n v u l s i v e
275
disorders
Table 1: Causes of death related to convulsive disorders for all ages and for those over the age of 5 years All ages
Febrile convulsions Convulsions Malnutrition Chest complications Drowning Asphyxia Status epilepticus Burns Poisoning Miscellaneous TOTAL
Age > 5 years
T
P
E
Total %
T
P
E
Total %
24 22 8 8 2 12 14 3 l 12 106
302 20 80 11 20 5 0 3 1 13 455
71 146 31 41 6 3 5 1 0 16 320
396 186 119 60 28 20 19 7 2 41 881
1 4 6 1 2 2 9 3 1 4 32
27 12 77 1 20 4 0 2 1 9 126
5 20 25 3 6 3 5 1 0 9 72
33 36 108 5 28 9 14 6 2 22 230
44.9 21.1 13.5 6.81 3.17 2.27 2.15 0.79 0.22 4.65 100
14.3 15.6 46.9 2.2 12.2 3.9 6.1 2.6 0.9 9.6 100
T, Town, P, Periphery, E, Estates.
70
(a) 60 200 180 /
50
(a)
160
40
-,
140 "o
30
120
~6 100
20
!,
E
80
~
60 _
'\\ \
,-
.
\
/
20 <1
I-5
6-10
1/-15
16-20
8
I
21-25
26-30
31-35
36-40
""
>40
(b)
7
i
6 -
5
z
3
/ \
/
\
~
/',
I
~
i
,,
i
:
/..",,
I
; i
~,
'\
-.-" "" "" ~
"~" '~. ,,~.
i
1967
1972
18 .
.
.
1977
lff
] 2 -\\ 10
\\ \\
'
"/I
.. •, . - . . . -
--.-._'- ~.. ........ ..~ .....
11-15
16-20
21-25
}6-30
~
-
, ..... 6-10
1987
.
I I-5
1982
-.
iA
2
0 r <1
~ ~ .~ ~ ~ ~ ~
0 , . ,
8
.
"'. ~ ' ~ . • •
l0
40 _
4
r
31-35
36-40
:,40
Fig. 3: a, Age at death due to febrile convulsions, convulsions, chest complications and malnutrition. - - , Febrile convulsions; - - , convulsions; ---, chest complications; . . . . , malnutrition, b, Age at death due to status epilepticus, burns and drowning. - - . , status epilepticus;---, burns; , drowning.
1967
1972
1977
~ ..... 1982
. 1987
Fig. 4: a, Proportion of deaths related to convulsive disorders in the three geographical divisions during 1967 to 1987 at five-year intervals. &, Town; II, periphery; 4,, estates, b, Proportion of deaths due to four common causes in the three geographic divisions during 1967 to 1987 at five-year intervals. II, Febrile convulsions; 4,, convulsions; ,t, malnutrition; O, chest complications.
276
District, accounting for 23.7 deaths per 1000 total deaths during the 20-year period. Over 70% of the deaths occurred in infancy and early childhood, and most of the deaths occurred outside the town area. The most common cause accounting for the deaths was 'febrile convulsions'. Most of the deaths (76%) attributed to febrile convulsions were from the periphery, and in the periphery 'febrile convulsions' was the most frequent (66.4%) diagnosis of deaths related to convulsive disorders. Febrile seizures are a common acute neurologic disturbance of childhood. A house-to-house survey of 577 families in the Kandy District revealed that 4.73% of the children had experienced febrile convulsions in the past 6. Febrile seizures are generally considered a benign condition. But, the very high mortality attributed to febrile convulsions in the DCs raises the question whether the seizures accompanying fevers in the tropics are 'febrile seizures' in the way the term is used in the West, or in fact the result of direct cerebral insult from infection 7. Osuntokun s remarked that febrile convulsions in the African child was not a benign condition. In Nigeria, the mortality of febrile convulsions was 28%, and the morbidity (hemiplegia, cortical blindness, iatrogenic burns with subsequent contractures, conjunctivitis, etc.) was high 9. Among survivors of febrile convulsions, 30% developed recurrent nonfebrile seizures within a period of five years I°. The present study shows that children who develop febrile seizures, particularly in the periphery, succumb to the underlying disease without proper diagnosis or treatment, and the deaths are attributed to 'febrile seizures'. 'Convulsions', the next most common diagnosis was made largely in the estates (78%), where it was the most frequent (45.6%) diagnosis of deaths related to convulsive disorders. 'Convulsions' included neonatal convulsions, prematurity and convulsions, infantile convulsions, and convulsions complicated by worm infestation. It is likely that central nervous system and other infections presenting with seizures came under this category. The perceived relationship between convulsions and worm infestations is noteworthy. Worm infestations are common in rural areas and estates. Worm infestation by itself does not cause convulsions, but a patient may vomit round worms during febrile illnesses and following seizures, which probably is the basis for the association between convulsions and worm infestation. Malnutrition complicating convulsions was another unusual diagnosis, most common
N. Senanayake & H. Peiris
(67.2%) in the periphery, which affected children as well as adults. These presumably are patients with frequent seizures who are neglected and become malnourished. Chest complications as the cause of death was most frequent (68.3%) in the estates, which is a reflection of the poor management of convulsive seizures. Forcing medicine and other liquids by mouth during or soon after a convulsion is common practice in these areas. Traditional physicians, in addition, administer medicinal oils through nasal passages as a treatment for convulsions. These practices have, no doubt, contributed to the high incidence of chest complications following convulsions in rural areas. Status epilepticus accounted for 2.15% of the deaths. There was no specific age group for the deaths. Most of the deaths were recorded in the Town area, presumably from the two general hospitals. However, there were some deaths in the estates attributed to status epilepticus, which meant that they died before transfer to a general hospital in the city. Drowning accounted for 3.17% of the deaths, and the victims were adolescents and adults. Most of the deaths had occurred in the periphery. In most villages, the source of drinking water is a well, which very often, is unprotected. For bathing, most villagers use a well or a stream. Patients with epilepsy can die by falling into a well or a stream during a seizure. Deaths due to burns had occurred mainly in the periphery or in the town. Some of the deaths recorded in the town area were probably patients transferred from the periphery to hospitals in the city. Because electricity is not available in rural areas, people use makeshift kerosene bottle-lamps. With slight disturbance these lamps can topple spilling kerosene and causing a fire. Children do their school work keeping a bottle-lamp on the desk at arm's length, and those with epilepsy are at risk of burns during a seizure. Similarly, women with epilepsy run the risk of burns in the kitchen because food is cooked using firewood in open hearths. Deaths due to poisoning were presumably suicides, rather than accidental overdosing with antiepileptic drugs. Sri Lanka has a very high incidence of suicide, and self-poisoning is by far the most preferred method II. Pesticides are the most common agent used ~-', which is much more lethal than an overdose of antiepileptic drugs. Patients with uncontrolled epilepsy, because of the physical disability as well as the social unacceptance and stigma may resort to suicide by taking poison. The mortality figures for drowning,
Mortality related to convulsive disorders
burns, and poisoning related to convulsions in this study are probably an underestimate, because the diagnosis of epilepsy could have escaped mention in the death certificate in many other cases. The mortality due to convulsive disorders showed a marked decrease during the 20-year period, and it was most evident in the periphery. This decrease is probably due to a decrease in the number of cases diagnosed as 'febrile convulsions' and 'convulsions'. It is likely that because of better public awareness and improved health facilities, children with convulsions receive early medical attention and correct treatment for the underlying disease. While appreciating the limitations of epidemiological studies based on DC, we believe that our data which compare the pattern of mortality in the Kandy District over two decades provide useful insight into the causes of death related to convulsive disorders in a developing tropical country. Standardized mortality ratios could not be computed, because the reference population for the study could not be defined. This is largely because patients are transferred from other districts for specialized care, and deaths of such patients registered in the Kandy District can give a spuriously high mortality rate. However, the proportional mortality ratios reported in our study highlight the causes of death which are most frequent in people with convulsive disorders. Although a decrease in the mortality ratio has been observed during the 20-year period, it can be reduced further by taking preventative measures. The public needs to be educated about the correct management of childhood convulsions. Special emphasis should be made about the dangers of forcing medicine and other fluids orally or intranasally into an unconscious person. With regard to epilepsy, early medical intervention can minimize the physical and psychological trauma caused by recurrent seizures. The community project in the Kandy District in the early 1980s revealed that more than half the number of patients with epilepsy detected at the survey were not taking any medical treatment -~. Appropriate antiepileptic medication and compliance can
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prevent or at least reduce the incidence of complications such as status epilepticus and injuries associated with seizures. General advice should be given to patients and their families to avoid dangers during a seizure. Precautions such as replacing makeshift bottle-lamps with better designed safety lamps will be of benefit not only to patients with convulsive disorders, but to the rural poor in general, in preventing unfortunate home accidents which may cause permanent disability or cost their lives.
REFERENCES 1. Senanayake, N. and Roman, G.C. Epidemiology of epilepsy in developing countries. Bulletin of the World Health Organization 1993" 71: 247-258. 2. Senanayake, N. and Roman, G.C. Epidemiology of epilepsy in the tropics. Journal of Tropical and Geographical Neurology 1992" 2: 10-19. 3. Senanayake, N. Epilepsy control in a developing country: the challenge of tomorrow. Ceylon Medical Journal 1987; 32: 181-99. 4. Senanayake, N. and Meinardi, H. Improvement of the care for people with epilepsy in rural areas of a developing country In: Advances of Epileptology. Vol. 17 (Eds J. Manelis, E. Bental, J.N. Loeber and F.E. Dreifuss). New York, Raven Press, 1989: pp. 441-444. 5. Massey, E.W. and Schoenberg, B.S. Mortality from epilepsy, international patterns and changes over time. Neuroepidemiology 1985; 4" 65-70. 6. Sanmuganathan, P.S. and Senanayake, N. An epidemiological study of febrile seizures in a rural community in Sri Lanka. Neurology India 1994; 42(Suppl. 4): 33. 7. Senanayake, N. and Roman, G.C. Aetiological factors of epilepsy in the tropics. Journal of Tropical and Geographical Neurology 1991; 1: 69-80. 8. Osuntokun, B.O. Malaria and the nervous system. African Journal of Medical Science 1983; 12: 165-172. 9. Osuntokun, B.O., Odeku, E.L. and Sinnettee, C.H. Convulsive disorders in Nigerians. East African Medical Journal 1969; 46: 385-394. 10. Osuntokun, B.O. Treatment of epilepsy with special reference to developing countries. Progress in Neuropsychopharmacology 1979; 3: 81-94. 1 I. Weerackody, C. Some features of attempted suicide in Sri Lanka. In: Suicide in Sri Lanka (Ed. P. de Silva). Kandy, Institute of Fundamental Studies, 1989: pp. 41-50. 12. Senanayake, N. and Peiris, H. Mortality due to poisoning in a developing agricultural country: trends over 20 years. Human and Experimental Toxicology 1995; 14: (in press).